Experience is our most valuable teacher, but only if we are willing to learn from it

In the (UK) Telegraph, Janet Daley writes:

The failure of communism should have been, after all, not just a turning point in geo-political power – the ending of the Cold War and the break-up of the Warsaw Pact – but in modern thinking about the state and its relationship to the economy, about collectivism vs individualism, and about public vs private power. Where was the discussion, the trenchant analysis, or the fundamental debate about how and why the collectivist solutions failed, which should have been so pervasive that it would have percolated down from the educated classes to the bright 18-year-olds? Fascism is so thoroughly (and, of course, rightly) repudiated that even the use of the word as a casual slur is considered slanderous, while communism, which enslaved more people for longer (and also committed mass murder), is regarded with almost sentimental condescension.

So why do so many of the world's leaders and thinkers behave as if there were no lessons to learn from the failures of the 20th century?  With over a hundred million people having died as a result of national socialism and international socialism, don't we owe it to them to learn from their sacrifice?

The most common answer that I hear from liberals is that socialism failed because "the wrong people were in charge."  This, of course,  misses the point: in any system involving human beings, there will always be times when the "wrong people" are in charge.  Any sensible system  should be designed to withstand that.  As documented by the Federalist Papers, the US Constitution was drafted by people who understood this well.  Liberals, leftists, socialists, and communists have never understood this or even acknowledged it as a legitimate topic for discussion.  John Hinderaker explains:

[Leftism] has always been based, for the most part, on hate and envy. So when Communism was conclusively proved to be a failure, leftists (including not only leftists in politics, but more important, leftists in the media and in academia) didn’t change their minds or admit their mistake. For in their eyes, while there may have been disappointment, there was no mistake. Their resentments and hatreds remained.

Liberalism is not a philosophy.  It is an emotion.